title: A dynamic method based on the specific substrate uptake rate to set up a feeding strategy for Pichia pastoris.
abstract: BACKGROUND
  Pichia pastoris is one of the most important host organisms for the recombinant production of proteins in industrial biotechnology. To date, strain specific parameters, which are needed to set up feeding profiles for fed batch cultivations, are determined by time-consuming continuous cultures or consecutive fed batch cultivations, operated at different parameter sets.
  
  
  RESULTS
  Here, we developed a novel approach based on fast and easy to do batch cultivations with methanol pulses enabling a more rapid determination of the strain specific parameters specific substrate uptake rate qs, specific productivity qp and the adaption time (Δtimeadapt) of the culture to methanol. Based on qs, an innovative feeding strategy to increase the productivity of a recombinant Pichia pastoris strain was developed. Higher specific substrate uptake rates resulted in increased specific productivity, which also showed a time dependent trajectory. A dynamic feeding strategy, where the setpoints for qs were increased stepwise until a qs max of 2.0 mmol·g-1·h-1 resulted in the highest specific productivity of 11 U·g-1·h-1.
  
  
  CONCLUSIONS
  Our strategy describes a novel and fast approach to determine strain specific parameters of a recombinant Pichia pastoris strain to set up feeding profiles solely based on the specific substrate uptake rate. This approach is generic and will allow application to other products and other hosts.
authors.affiliation: Vienna University of Technology, Institute of Chemical Engineering, Research Area Biochemical Engineering, Vienna, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Dietzsch
authors.forename: Oliver
authors.initials: O
authors.lastname: Spadiut
authors.forename: Christoph
authors.initials: C
authors.lastname: Herwig
mesh_terms: D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D000432:Methanol / Q000378:metabolism; D010843:Pichia / Q000254:growth & development / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D013379:Substrate Specificity
chemical_list: D003470:Culture Media; D011994:Recombinant Proteins; D006735:Horseradish Peroxidase; D000432:Methanol